Along with a recent spread of mobile telephones, the service area has been developed based on a cellular communication system as a basic infrastructure for mobile networks, in which it is demanded to mount thereon a function taking into account a convenience for maintenance as the number of device or equipment adopted is increased. Also in a wireless device, the mounting demand regarding the detection of a Voltage Standing Wave Ratio (VSWR) in addition to a transmission signal level (Lt) and a reception power is being generalized.
An arrangement of a related art wireless transmitting/receiving device is depicted in FIG. 8. In this wireless transmitting/receiving device, a transmitting side circuit is composed of a transmitting portion 1 and directional couplers 2, 21 and a receiving side circuit is composed of a directional coupler 7 and a receiving portion 9, where both of the circuits are adapted to be switched over between connections with a bandpass filter (BPF) 5 and an antenna 6 by a transmission/reception switch 40 under the control of a TDD switching signal STDD.
At first, in a transmission period (duration) prescribed by the TDD method the transmission/reception switch 40 is switched over to a transmitting side terminal (a) as depicted, by the TDD switching signal STDD, at which time the output of the transmitting portion 1 having received a transmission signal St toward the antenna 6 is detected in the form of a transmission signal level (transmission voltage) Lt by a detector (DET) 3 through the coupler 2. Together with this, a reflecting signal level (reflection voltage) Li of the transmission signal St reflected by the antenna 6 is detected by a detector 22 through a coupler 21.
Voltage Standing Wave Ratio (VSWR) is expressed by a function of a ratio between a traveling wave (transmission signal level Lt) and a reflection wave (reflection signal level Li), so that with these two detection values Pt and Pi a calculator 10 can calculate the voltage standing wave ratio (VSWR).
Also the transmission/reception switch 40 is switched over to a receiving side terminal (b) by the TDD switching signal STDD, at which time a reception signal level (reception voltage) Lr is detected by a detector 8 through a coupler 7, where a reception signal Sr is obtained from the receiving portion (LAN: Low Noise Amplifier) 9.
The transmission signal level Lt and the reception signal level Lr are, as depicted, converted to the transmission power Pt and the reception power Pr respectively by a power detectors 51 and 52, which will be similarly applied to the following descriptions.
On the other hand, there is an impedance matching device comprising a standing wave ratio detection section measuring voltages of each of plural positions on a transmission line from a transmission section leading to an antenna to detect a standing wave ratio, an impedance calculation section recognizing a current impedance toward the antenna when viewed from the transmission line based on the standing waves on the transmission line, a setting matching table storing a setting value of a prescribed matching element as a list for the matching of the impedance between the transmission section and the impedance of the antenna, a variable matching section provided for impedance adjustment to an input terminal of the antenna receiving transmission power from the transmission line, and an arithmetic control section controlling the impedance of the matching element of the variable matching section to be a prescribed impedance based on the current impedance and an impedance from the setting matching table (See e.g. Japanese Laid-open Patent Publication No. 08-97733).
Also, there is a radio base station testing method and tester in which RF-SWs switch routes of signals transmitted/received to/from a terminal function unit attached to a base station 100; RF-SWs connect the terminal function unit to desired radio analog units; a test function controller controls switchings of the RF-SWs according to information designated by a maintenance apparatus (OMC); a base station controller controls one or a plurality of tests according to received test class information among (1) an antenna trouble test for obtaining the voltage standing wave ratio based on the transmission power of the terminal function unit, (2) a receiver trouble test for obtaining the receiver sensitivity based on the transmission power of the terminal function unit after adjusting the packet error rate, and (3) a transmitter trouble test for obtaining transmission power from the radio analog units based on the reception power value of the terminal function unit (See e.g. Japanese Laid-open Patent Publication No. 2005-151189).
Thus in the related art depicted in FIG. 8, two pairs of a directional coupler and a detector are mounted on the transmitting side circuit to detect the transmission signal level Lt and the reflection signal level Li, thereby detecting the VSWR while a single pair of a directional coupler and a detector is mounted on the receiving side circuit to detect the reception signal level Lr.
However, such a related art wireless transmitting/receiving device requires three pairs of a coupler and a detector for detecting the transmission signal level Lt, the VSWR and the reception signal level Lr. Furthermore, in case of the TDD method, the transmission period and the reception period are separated on a time axis, so that in the transmission period the receiving side circuit takes a pause while in the reception period the transmitting side circuit takes a pause, resulting in a very low circuit operation rate.